The following entry is the realization of the first part of the modernization project of the power supply system with implementing a new monitoring and control system. Description of the assumptions for the project is available at the blog home page at:http://moje-nocne-niebo.blogspot.com/

Module for monitoring of the power supply parameters (installed in a box with a control computer)

Constant monitoring of voltage and current drawn from the battery

Temperature and humidity control inside the computer box for control of the cooling fan to prevent for overheating.

Collecting and transferring data by radio to the control and power supply module (module installed directly on the telescope)

The module has been designed based on microcontroller ARDUINO PRO MINI 328. The microcontroller requires 5VDC so taking power from battery 12VDC it was necessary to use a voltage stabilizer LM7805 (capacitors C1 and C2 are the voltage filters ). The system is integrated with voltage divider consisting of resistors R1 and R2, which is used to measure battery voltage. The divider is required to lower supply voltage to the level supported by the microcontroller (below 5V). Another element of the measuring system is ACS711 - with his help monitored is the total current consumption from the battery. The module is also equipped with a temperature and humidity sensor DHT22. Because the control computer connected to the telescope works in the closed box there is a possibility of rising temperatures and overheating which can lead to the malfunction of the computer. As the counteraction the box is equipped with cooling fan, pumping air into the box. The fan may operate at three different load levels (30%, 60%, 100%). His work is controlled by a temperature sensor DHT22 and a field-effect transistor IRLZ44N. DHT22 sensor also measures humidity. If the humidity of the air inside the box rises to near the dew point then interlook of the cooling fan is activated. In consequence of that cooling fan is immediately stopped (PC protection). At the end, all relevant data, such as voltage, total current consumption of the battery, temperature, humidity and condition of the fan are transmitted by radio to the power and control box installed on the telescope.